Happygun is a tall man with long black hair, a long pointed nose, and a triple pointed chin. He wears a purple coat with pink inner edges that exposes his chest.
In his original concept art, he wore a light colored coat with light colored buttons and lines at the end of the sleeves over a light colored vest underneath. Under the vest, he wore a button up white shirt. He also has a light colored sash and dark colored pants with long boots that go to his thighs.
Since Happygun was willing to put his life on the line to save Ace from execution, it can be deduced that Happygun is a person that values loyalty and friendship. Furthermore, since he was willing to brave the fight against Marine Headquarters, it can be concluded that Happygun is a daring and fearless pirate captain.
Abilities and Powers
Happygun is a fearsome pirate who has managed to achieve an infamous reputation in the New World. Nothing is known about his combat abilities, but it can be assumed that it is befitting of his status as an infamous pirate.
Summit War Saga
When Portgas D. Ace was to be executed at Marineford, Happygun and his crew joined forces with the Whitebeard Pirates in order to save him from execution. While the Marines were bracing for the arrival of the pirates, Happygun and the allied fleet of the 43 subordinate captains caught them by surprise when the fleet suddenly appeared out of nowhere just off the shores of Marineford.
After Ace was killed by Akainu, Jinbe tried to save Luffy from being killed by the Marine Admiral. However, Akainu then punched straight through Jinbe, and Happygun, Ninth, and Pavlik watched in horror at the sight before their eyes. 
- One Piece Manga — Vol. 59 Chapter 578 (p. 11), Happygun makes his debut.
- One Piece Green: Secret Pieces (p. 361), Happygun's name is revealed.
- One Piece Manga — Vol. 56 Chapter 551 (p. 12-13), The allied fleet appears off the shores of Marineford.
- One Piece Manga — Vol. 59 Chapter 580 (p. 15), Sengoku calls an end to the war.